The invention relates to a conveyor mat built up from modules manufactured in one whole from plastic, each module consisting of a number of substantially equally spaced apart hinge plates and an end hinge plate, each extending over substantially the entire length of the module and each having both ends provided with hinge loops, the hinge plates of a module being intercoupled by at least one transverse rib and there being provided, adjacent at least the outer hinge plate at the transverse end of the module located opposite the end hinge plate, a plate-shaped part extending parallel to said hinge plate over a distance smaller than the distance between the hinge loops in a hinge plate and coupled to the at least one rib of the module and whose top side lies substantially in one plane with the top side of the mat, the end hinge plates of the successive modules being alternately located on one and on the other lateral side of the conveyor mat, the ends of the hinge plates on a longitudinal side of a module being located between the ends of the hinge plates of a module adjoining in longitudinal direction of the mat, the hinge loops of the two modules being substantially in alignment and intercoupled by a hinge pin extending through the hinge loops.
Such modular conveyor mat is known from EP-A-0 598 453. This patent application describes a conveyor mat consisting of first and second modules assembled in a brickstone connection, the second modules forming so-called end modules, present exclusively at the outer edge of the mat, viz alternately with a module of the first type, viewed in the conveying direction of the mat. This patent application also describes the possibility of manufacturing a narrow conveyor mat, consisting exclusively of second or end modules, said modules being alternately arranged, such that at each lateral edge of the mat a wide end hinge plate and a relatively narrow plate portion are alternately present.
In so-called xe2x80x9cshrink-wrapxe2x80x9d machines, narrow conveyor mats are used, because in such machines it is desired that bottles, cans and the like to be packed can be conveyed in a single line. Up to the present, such conveyor mats have been manufactured by shortening a wide mat in transverse direction by a sawing operation. This entails the drawback of creating additional labor costs and of the mat having an irregular lateral edge. A further problem is that the known mats are guided in a slot-shaped section. Consequently, it is not possible to form, if so desired, a wider conveying surface consisting of several tracks in close side-by-side relationship, because the lateral edges of adjacent mats cannot lie in close side-by-side relationship.
The object of the invention is to provide a conveyor mat for such practical applications which does not have the above drawbacks. To that end, according to a first aspect, the invention provides a conveyor mat of the above-mentioned type, characterized in that of at least a number of modules in the conveyor mat, the end hinge plate and/or the plate-shaped part that is located opposite the end hinge plate extends to a position below the surface of the mat formed by the successive modules, the arrangement being such that the thus formed downward extension forms a lateral guide for the conveyor mat.
In accordance with a second aspect, the invention provides a conveyor mat of the above type, characterized in that for each module of the conveyor mat, the end hinge plate and the plate-shaped part that is located opposite the end hinge plate are provided with a recess extending throughout the length of the module and adjoining the bottom face of the mat formed by the successive modules, the arrangement being such that the recesses can cooperate with a guide of U-shaped cross section.
Surprisingly, it has been found that by the features according to the invention, a conveyor mat for use with shrink-wrap machines is readily obtained, which conveyor mat can be manufactured in an inexpensive manner, which has a substantially completely smooth and flat lateral edge and can be guided over a tubular member or a U-shaped section located between the downwardly directed guide faces formed on either side of the mat or engaging the recesses present on either side of the mat respectively, enabling adjacent mats to be built with their lateral edges closely against one another, if so desired.
Further advantages are that the mat can easily be lifted from the section due to the lack of so-called tabs or bevels for guidance. Also, the mat according to the invention can be extremely narrow, for instance 30 mm, which may be desired for specific practical applications, such as the transport of cans of beverage.
Preferably, also in the mat according to the first aspect of the invention, both the end hinge plate and the plate-shaped part of each module in the mat are designed with a downward extension. Further, adjacent each hinge plate there is preferably provided a plate-shaped part.